Wavelength tunable lasers have many applications in telecommunications and optical sensing. Usually, a tunable laser will output a specific set of wavelengths (or frequencies) which can be selected on demand. Tunable lasers generally require a mechanism to control their output frequencies; and the parameters needed to set the output frequencies are usually characterized and stored in non-volatile memories during a calibration process. These parameters are later looked up and loaded for wavelength tuning during the operation of a tunable laser. The calibration process sometimes involves a multi-dimensional search, which could be a lengthy and time consuming process, and adds significant cost to the manufacturing of tunable lasers.
Referring to FIG. 1A, a tunable laser calibration system 100a conventionally includes a wavelength analyzer 110, an optical spectrum analyzer 120, and an oscilloscope 130, each receiving an output signal Sout from a tunable laser 200. An optical splitter 140 splits the output signal Sout for delivery to the wavelength analyzer 110, the optical spectrum analyzer 120, and the oscilloscope 130. An optical/electrical converter 142 converts the optical signal Sout to an electrical signal for receipt by the oscilloscope 130. The calibration system 100a generally uses the optical spectrum analyzer 120 and the oscilloscope 130 to measure an output modulation amplitude (OMA) and an extinction ratio (ER) of a tunable laser 200. The calibration system 100a generally uses the wavelength analyzer 110 to calibrate a wavelength reference.